Being a starting pitcher isn't easy and it's certainly not easy to be a starting pitcher that belongs in the elite class with guys like Clayton Kershaw, Chris Sale, Corey Kluber, and Max Scherzer. After all, it takes hours upon hours of practice, perfecting your craft, and trying to identify which pitches coincide best with your game. In addition, don't discount the fact of having to watch hundreds of hours of video on opposing hitters or having to study scouting reports either, all with the help of a couple of big league catchers.

With that being said, as is the case every season, there is always a few starting pitchers, who have basically reinvented themselves or developed an entirely new game plan, to make them look like new pitchers. Now, they haven't made the adjustments to automatically shoot into the elite class category, but they have made enough adjustments to make an impact and their team is benefitting from that. So far this season, the two names that stand out the most are: Nathan Eovaldi and Clay Buchholz.

1. Nathan Eovaldi (Tampa Bay Rays-Boston Red Sox): Nathan Eovaldi is the prime example of someone who has come back stronger than ever following Tommy John surgery. Eovaldi started the year with the Tampa Bay Rays before getting traded to the Boston Red Sox and Tampa Bay is a genius for making, what looked like a bargain signing, into a trade that should have substantial impact on the organization moving forward. Eovaldi signed a two-year, $4 million dollar deal during the 2016 offseason and will be a free agent at the end of the season, but Boston identified someone who can help them down the stretch as well as come October, either in the starting rotation or the bullpen. It was just two years ago when Eovaldi posted a 4.76 ERA over 124.2 innings of work with a 4.97 FIP and a walks-per-9 rate of 2.9. However, this season has looked like an entirely different animal for Eovaldi, who has a cumulative ERA of 3.74 over 74.2 innings, along with a strikeouts-per-9 rate of 7.5 with both organizations. Furthermore, through 3 starts with the Boston Red Sox, Nathan Eovaldi has put up a 2.04 ERA over 17.2 IP and has a 3.38 FIP over that time.

A big reason why Eovaldi has become a new pitcher in some sense is based on the pitch repertoire that he is relying on. Below is a diagram that shows Eovaldi's pitch chart and his usage over the last three seasons. From L to R on the chart below: fastball, slider, cutter, curveball, changeup, and split-fingered fastball.

Over the past three seasons, Eovaldi is practically throwing his fastball and slider about 10% less of the time. Not a drastic difference, but something to still note. What's even more fascinating is when you look at how often he is throwing his cutter this season compared to last. As the chart illustrates, Eovaldi is throwing his cutter 31.6% of the time this year compared to 7.3% of the time last season. Furthermore, Eovaldi is throwing his curveball about 8% less over the past three seasons and has eliminated the use of his changeup entirely, while also laying back on his reliance of his split-fingered fastball. From last season to this year, Eovaldi's usage of his split-fingered fastball has dropped from 22.9% to 12.6%, as seen on the chart.

A big reason why Nathan Eovaldi has basically reinvented himself is because he is throwing his cutter more and hitting the low-to-mid 90's while doing so. Every other pitch is virtually the same in terms of average velocity, but one interesting note is the difference in velocity on his curveball. Between last season and this year, Eovaldi has added about 3 MPH to that pitch (74.7 MPH last season compared to 77.9 MPH this year).

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​​2. Clay Buchholz (Kansas City Royals Minor Leagues-Arizona Diamondbacks): Clay Buchholz is another one of those guys who has basically come out of nowhere and has reinvented himself. Earlier this season, when the Arizona Diamondbacks got word that they would be losing Taijuan Walker to Tommy John surgery, Mike Hazen & Company immediately went outside the organization and looked for help. Buchholz started the year in the minor leagues with the Kansas City Royals, but was later released before being picked up by Arizona. After recording a 12.27 ERA over 7.1 innings of work last year with the Philadelphia Phillies, Buchholz has a 2.67 ERA over 64.0 IP, so far this year with the Arizona Diamondbacks. In addition, his WHIP of 1.14, is the lowest of his big league career dating back to 2013 and he's got an 82.6 left on-base percentage this year, the lowest dating back to 2013. As is the case with Nathan Eovaldi, Clay Buchholz is primed to hit free agency this winter, but not before trying to help the Arizona Diamondbacks win the National League West.

Buchholz hasn't altered his game to the point of Nathan Eovaldi to this point, but he is experiencing somewhat of a career resurgence at the age of 33. Here is the pitch type and usage chart for Buchholz over the past two seasons:

As you can see from the chart, the differences between Buchholz's pitch repertoire is not that different this season compared to last year. Based on the data, Buchholz is relying on his fastball about 1% more often, his cutter almost 2% less (25.0% last season compared to 23.6% this year), his curveball less (20.1% last year versus 18.5% so far this season), and the difference between his changeup is 16.6% thus far compared to 14.6% over the entire span of last season. Again, very small differences, but nonetheless important to note as we all try to discover why Clay Buchholz has basically become an old version of himself.

Furthermore, Arizona's stellar defense has also played somewhat of a role in helping Clay Buchholz to reinvent himself and find the old version of himself again. Buchholz isn't really the effective groundball pitcher that he was back in 2014 or 2015 with the Boston Red Sox, when he sported a groundball percentage in the mid-to-high 40's, but he still has a 40.1% ground ball rate, which is important given the hitting environment of Chase Field. In addition to that, when Buchholz does induce contact, often times it tends to be more medium-to-hard contact. So far this year, Buchholz has a soft contact rate of 16.3%, a medium contact rate of 46.8%, and a hard contact rate of 36.8%, which all adds up to a 4.12 SIERA (Skill-Interactive ERA). That number is much better than the SIERA Buchholz had last year with the Phillies - 5.82.

While both Nathan Eovaldi and Clay Buchholz have reinvented themselves, they still aren't in that upper echelon of starting pitchers, but the changes and adjustments that they have made are working, as illustrated by their recent success. The best part is that both are on contending teams and will likely play a large role in their team's success during the remainder of the season as well as come October, as both organizations look to make it to the World Series.